RESUMO
Cyclooxygenases (COXs) play a pivotal role in inflammation, a complex phenomenon required in human defense, but also involved in the emergence of insidious human disorders. Currently-used COX-1 inhibitors (Non-Steroidal Anti-Inflammatory Drugs-NSAIDs), as the most frequent choices for the treatment of chronic inflammatory diseases, have been identified to be associated with a variety of adverse drug reactions, especially dyspepsia, as well as peptic ulcer, which lead to diminished output. Moreover, the structural similarities of COX- 1 and -2, along with the availability of comprehensive information about the three-dimensional structure of COX- 2, co-crystallized with various inhibitors, search selective COX-2 inhibitors a formidable challenge. COX-2 inhibitors were shown to minimize the incidence of metastasis in cancer patients when administered preoperatively. Developing selective COX-2 inhibitors to tackle both cancer and chronic inflammatory illnesses has been identified as a promising research direction in recent decades. Identifying innovative scaffolds to integrate as the major component of future COX-2 inhibitors is critical in this regard. The presence of a central, α, ß-unsaturated carbonyl- containing scaffold, as a characteristic structural pattern in many selective COX-2 inhibitors, along with a huge count of chalcone-based anticancer agents representing the basic idea of this review; providing a survey of the most recently published literature concerning development of chalcone analogs as novel COX-2 inhibitors until 2022 with efficient anticancer activity. A brief overview of the most recent developments concerning structure- activity relationship insights and mechanisms is also reported, helping pave the road for additional investigation.
Assuntos
Chalconas , Neoplasias , Humanos , Inibidores de Ciclo-Oxigenase 2/farmacologia , Inibidores de Ciclo-Oxigenase 2/uso terapêutico , Anti-Inflamatórios não Esteroides/farmacologia , Ciclo-Oxigenase 2 , Neoplasias/tratamento farmacológicoRESUMO
Losartan, a highly effective blood pressure-lowering agent, has been widely used for the treatment of hypertension. A fast and reliable method for the determination of losartan was highly desirable to support formulation screening and quality control. A first-derivative UV spectroscopic method and HPLC were developed for the determination of losartan in the tablet dosage form. The first-derivative spectrum recorded between 220 and 320 nm and a zero-crossing technique for first-derivative measurement at 232.5 nm were selected. The selectivity and sensitivity of the method was in desirable range. In comparison with the direct UV method, first-derivative UV spectroscopy has a definite trough without any interference from UV absorbing-excipients. This method is also fast and economical in comparison with the more time-consuming HPLC method regularly used for formulation screening and quality control and can be used routinely by any laboratory possessing a spectrophotometer with a derivative accessory. The linear concentration ranges were 2-50 microg ml(-1), (D(1)=-0.0159C-0.0056, r=0.9994, n=6). Between-days CV of < or =2.9%, within-day CV of < or =2.1%, and analytical recovery close to 98.1% show the suitability of the method for determination in quality control.